(a) Field of the Invention:
This invention relates to a plate type heat exchanger and more particularly it relates to a plate type heat exchanger referred to as a collision-jet type plate heat exchanger.
(b) Description of the Prior Art:
Generally, the plate type heat exchanger effects heat exchange between two fluids flowing along heat transfer plates and a conventional plate type heat exchanger has disadvantages. Because of the construction in which a complex pattern is formed on the heat transfer surface to disturb the flow of fluid in order to obtain a high thermal conductivity, it cannot be helped to suffer a considerable pressure loss. Therefore, in an actual design aspect, it sometimes happens that a high thermal conductivity cannot be attained because of the need of reducing the pressure loss. Further, in the case of highly viscous fluids, such fluid often fails to reach the regions in the heat transfer surfaces farther from the fluid inlet and outlet ports. This means that the deviated flow of fluid takes place on the heat transfer surfaces, so that high heat transfer performance cannot be obtained. Further, prolonged use results in the heat transfer surfaces being fouled, thus leading to substantial deterioration in the performance.
When consideration is given to a conventional heat exchanger in which the two fluids are steam and a cooling liquid and heat exchange therebetween results in the steam being condensed, i.e., a conventional condenser, it is seen that the conventional plate type condenser has disadvantages. That is, since the form of condensation of steam which takes place on the heat transfer surfaces is film-form condensation, it is impossible to attain a very high thermal conductivity. The flow of steam is influenced by the condensed condition on the heat transfer surfaces and the deviated flow and the like are liable to take place. Besides this, a very small amount of uncondensable gas contained in the steam stagnates on the heat transfer surfaces, hindering the improvement of the overall coefficient of heat transfer.